Apple leaves behind drives and ports at a breakneck pace, always looking to the future. With the Retina MacBook Pro they’ve even traded in screws for glue and solder in a number of instances. Apple has come to be known for this driving attitude in hardware innovation.

It happens more slowly and seldom with system software, but we have seen it before. We saw it with the transitions away from the classic Mac environment and Carbon. We see it in APIs, like the move to ARC and the deprecation of garbage collection. And we’re seeing it now with Gatekeeper and Sandboxing.

All these transitions are painful to somebody. Somewhere there was a guy who really wanted that serial port, disk drive, or that old app. It’s hard to be the one left behind. The early adopters usually manage to stay ahead of the curve, but changes catch up with all of us eventually. However, these transitions are also something we’ve come to expect from Apple. They help us to push forward ourselves, and for many Apple customers, that’s a big part of why we choose to be on this team.

iOS offered a clean break. Apple took advantage of it, and it had manifold benefits: simplicity, performance, power management, security. They demonstrated “Back to the Mac” in Lion as a collection of apps and features from iOS, but they didn’t speak much to these other benefits that are a big part of the platform’s success. Apple sees advantages in bringing some of the behind the scenes changes to the Mac as well, but it won’t come without ripping off a few of these Band-Aids.

The folly with the Sandboxing transition was that the Mac App Store was released before these rules were in place to enforce upon its apps. It would have been harder to argue against rules for a store that had never existed in the first place. But for whatever reason, Apple felt it was necessary, or at least to their benefit, to push out the store when they did.

Today we’re left with some developers stuck between a rock and a hard place. They made the jump to the store only to find themselves as persona non grata months down the road. I feel for them, and frankly I’m bummed to have to get their software the old fashioned way.

I’m hoping (as I’m certain Apple believes) that these growing pains will yield something more mature and valuable down the road. There is a reset of user expectation taking place. Apple sees a future where the boundary between apps and the system are clear to users who are mere mortals. Many more people will feel welcome in that future, as they already do on iOS. And hopefully the same revolution that the iOS App Store brought to the software industry will see rewards from the growing customer base of the Mac as well.

In the meantime, we can mourn the casualties, and do our best to push forward and make better software. Time will tell whether their loss was in vain.